This invention relates to a self-closing tilting valve which is sealingly insertable into a lid, provided with a valve mounting means, of a container filled with product under pressure, which valve comprises a central mandrel member having a base part and a tip part and an enveloping member having a head part containing an outlet opening and a foot part, at least one passageway for product being provided extending along the mandrel member from the container to the said outlet opening, and at least one sealing surface being provided at the interior wall of the enveloping member which sealing surface obturates the product passage when in closing position, by sealingly engaging a corresponding counter-surface of the mandrel member, which counter-surface is located within the range of the passageway, the tip part of the mandrel member being in contact with the surrounding head part of the enveloping member in closed as well as in open position, while one of the foot part and the base part is insertable in the valve mounting of the container lid.
A valve of this kind has been described in U.S. Pat. No. 2,831,620 to T. F. Schlicksupp. However, this kind of valve is not suitable for use with pressurized product-filled containers, in particular, when the internal excess pressure in the container reaches the usual values of, for instance, 3 to 5 bar. Such excess pressures would cause an expansion and/or lateral displacement of the bellow-type central zone provided in the enveloping member of Schlicksupp's valve and thus cause it to open unintentionally.
Valves of the Schlicksupp-type are, therefore, only used for liquids such as toilet water, skin lotions, perfumes and also for creams which are present in the container under no or much less excess pressure.
Another tilting valve of somewhat similar construction has been described in U.S. Pat. No. 3,920,165 to Robert S. Schultz. This valve would indeed be suitable for containers having contents under higher internal pressure. However, in this valve which contains, beside a mandrel member, an internal enveloping member and an external cap member, the tip part of the mandrel member does not remain in contact with the inner wall of the head part of the cap member when the valve is opened. Rather, a spacing apart occurs between both parts, while in the case of the tilting valve according to the invention as well as in the case of Schlicksupp's valve, these two parts should remain in contact with one another in the closed as well as in the opened position. A spacing apart between the two tiltably supported members of the Schultz valve jeopardizes a resealing of the valve after each opening stage, even when the dimensioning of the cap member and the internal enveloping member with respect to each other is very exact, because of the variable support means of the two members. For, the cap member must find support simultaneously on the container lid wall and against a shoulder provided in the sidewall of the enveloping member, which latter must in turn provide support for the mandrel member.